1. Field of the Invention
The present invention relates to error detection techniques, and more particularly to an error detection method and apparatus which are effective when applied to error detection and resumption processes in an information processor.
2. Description of the Prior Art
With the spread of information processors, influences attendant upon the shutdown of the processors are increasing, and it is indispensable to ensure the reliability of the processors for maintaining stable operation.
As an expedient for detecting the error of a central processing unit constituting the information processing system or any peripheral device connected thereto, therefore, microdiagnostics (MD) which decides the existence or nonexistence of the error through the execution of a microprogram has heretofore been common practice as disclosed in, for example, Japanese Patent Application Laid-Open No. 40943/1988 or No. 55645/1988.
More specifically, a microdiagnostic program is described at the level of the microprogram, it is loaded in part of a control storage at, e.g., the start-up of the system together with ordinary microprograms for controlling the operation of the central processing unit, and it is periodically executed, thereby intending to detect the presence of any hardware error.
On the other hand, as a technique for inspecting the information processor in software fashion, an error is detected by periodically starting a test program such as I/O patrol for checking a miscalculation or inspecting an input/output unit, at the level of an operating system by way of example.